The Analytical Core (Core B) will be organized to provide high quality, reproducible, low cost, automated high-throughput robotic analytical services to the four projects as well as the Animal Core (Core C). The core will be managed and staffed with experts who have demonstrated an ability to develop, engineer, and implement the assays necessary to support the proposed activities of the Analytical Core. The Analytical core will be organized around 4 major services/specific aims. Specific Aim 1: To provide high quality, reproducible automated assays to support Projects 1-3 and the Animal Core. Specific Aim 2: To provide genotyping services for projects #1 and #2. We will test for the presence of SNPs in GRK4, angiotensin converting enzyme (ACE l/D), aldosterone synthase, angiotensinogen, and ATIR using our previously published method {Bengra, 2002, 12446468} with a data reducfion method (Moore, Pub Med ID 12108579). Additional SNPs will be added as needs arise. Specific Aim 3: To provide cultured human renal proximal tubule cells for projects #1and #3 using a novel patent pending 3D cell culture method. We will also use our method to isolate individual renal proximal tubular cells (RPTCs) from fresh specimens of human urine in order to provide greater genetic diversity for studying human physiology, to correlate in vitro cellular responses to in vivo responses in the same patients as studied in Project 2. Specific Aim 4: To provide cellular imaging services to support projects #1 and #3. In addition, in support of project #2, we will perform human kidney slice culture and subsequent confocal analysis of DIR and DSR localization.